Image elements

ABSTRACT

THIS IS AN AUTOMATIC PROCESS FOR THE DETECTION OF LOCAL SIMILARITY BETWEEN TWO STRUCTURED DATA SETS IN ORDER TO ACHIEVE IMAGE REGISTRATION. A CLASS OF SEQUENTIAL SIMILARITY DETECTION PROCESSES FOR EFFECTING IMAGE REGISTRATION ARE DISCLOSED. THESE PROCESSES DETERMINE THE BEST MAPPING OF A SELECTED WINDOW AREA OF ONE OF THE DATA SETS ONTO THE OTHER DATA SET. REFERENCE POINTS FOR THE MAPPING ARE SELECTED SEQUENTIALLY AND FOR EACH REFERENCE POINT SELECTGED AN ERROR FUNCTION IS COMPUTED TO DETERMINE WHETHER THE WINDOW CORRELATES WITH THE SEARCH AREA AT THE SELECTED REFERENCE POINT. CORRELATION IS DETERMINED BY COMPARING THE ERROR FUNCTION TO A THRESHOLD SEQUENCE AND TERMINATING THE PROCESS FOR A PARTICULAR REFERENCE POINT WHEN THE ERROR VALUE EXCEEDS THE THRESHOLD VALUE.

DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16, 1969, 869 0.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Oflice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED JANUARY 7, 1975 930 O.Gr. 115

T93l,002 AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Daniel I. Barnea, Tel Aviv, Israel, and Harvey F. Silverman, Mohegan Lake, N.Y., assignors to International Business Machines Corporation, Armonk, N.Y. Continuation of abandoned application Ser. No. 263,482, June 16, 1972. This application Dec. 6, 1973, Ser. No.

Int. Cl. G06f 15/20 U.S. Cl. 444-1 14 Sheets Drawing. 28 Pages Specification SEARCH AREA S This is an automatic process for the detection of local similarity between two structured data sets in order to achieve image registration. A class of sequential similarity detection processes for effecting image registration are disclosed. These processes determine the best mapping of a selected window area. of one of the data sets onto the other data set. Reference points for the mapping are selected sequentially and for each reference point selected an error function is computed to determine whether the window correlates with the search area at the selected reference point. Correlation is determined by comparing the error function to a threshold sequence and terminating the process for a particular reference point when the error value exceeds the threshold value.

Jan. 7, 1975 D. l. BARNEA ETAL AUTOMATIC PnocEs FAST DIGITAL IMAGE REGISTRATION I 14 Sheets-Sheet 1 Original Filed June 16, 1972 ALLOWED RANGE OF REFERENCE POINTS i SEARCH AREA S WINDOW-W FIG.2

fl= IMAGE ELEMENTS Jan. 7, 1975 Original Filed June 16, 1972 FIG.4

D. BARNEA ET AL T930,002

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION l4 Sheets-Sheet 2 REGION WHERE THRESHOLD SEQUENCE CALCULATIONS NEED REGION WHERE NO LONGER BE DONE\ CALCULATIONS ARE ADDED fl= IMAGE ELEMENTS MEAN- DEVIATION THRESHOLD CURVES TI IMAGE ELEMENTS Jan. 7, 1975 1 3.1. BARNEA ETAL T930,002

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 5 FIG.

n IMAGE ELEMENTS FIGS l4 Sheets-Sheet 4 D. 1. BARNEA ETAL I ENTRY READ-IF OF RUNS NRUNS Jan. 7, 1975 AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 READ INTO GORE SEARCH AREAS G. H m I m J m K F6 F6 F6 F6 m 6.8 6 F F F6 6 2 K W6 22 4 S m SW SW T El v N SW S 0 G l.\ PNA IIM S W A H S L M EL TIN IIIII L Nm v R 0 P F L I W m UM 0D R 70344 0 c swsw 00 )A 4H I ME N Y \I X X n I122 SWSW IIIIIIII 5566 SWSW w 0 AS 0 Mm N I AT A w E NOQCAMH 6 I R R mm m G E .S R I WINDOW-W READ ORDERING PARAMETERS IS IND SET ARRAY FLAG(I)=O Jan. 7, 1975 D. I. BARNEA ETAL T930302 AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 5 APPLY RANDOM GEN. RANDU T0 GENERATE 2 RANDOM #5 BETWEEN 35\ NV=(LY-1)*W5+LX IS FLAG (NV)=0 YES L L FLAG(NV)=1 0 0 J=J+1 XN'(J)=LX-1 YN(J)=LY-1 |S'K 1000000? YES IS JZNLIST? WRITE OUT LIST .0 0 s4 FBG.6 ISNORMT=0? 1 YES ,NO Y

Jan. 7, 1975 D. l. BARNEA ETAL T93,002

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 6 I CALCULATE MEAN 1 N5 W4W(IJ) GREY LEvEL IWLEV= 2 3 0F WINDOW I=1 J=I L SUBROUTINE SMEAN1 Fl (3 66 mp w A (OBTAIN suNEAcE 0F MEAN VALUE & CALCULATE MEAN GREY LEVEL OF I WINDOW) CALCULATE SUMAOF I m FIRST W4 ELEMENTS OF I H(I)=2 S(I,J)

coLuMNs OFS J=1 CALCULATE SUM OF i W FIRST W3 ELEMENTSOF V(J)=2 S(I,J)

ROWSOFS H A CALCULATE wa UPPER LEFT 'TH('1)= 3 H(I) SUM Y I=1 OBTAIN AVERAGE LEVEL OF UPPER I NORMAL(1,1)=TH(1)/ITOT LEFT SUBIMAGE I OBTAIN REST OF NORMAHMWWMH m Jan. 7, 1975 D. l. BARNEA ETA!- AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 l4 Sheets-Sheet 7 Y OBTAIN NEW H(I)=H(I)-S(I,J)+S(I,J+W4) H VECTOR H To $4 w4 OBTAIN NEWSTART I TH(1)-TH(I) V(J) V(I+W4) 35 I ITOT CALCULATE TH(M)=TH(I)-H(I)+H(W3) REST OF I NORMAL(M,J1)=TH(M.)/ITOT SURFACE I I=1TOS3-W3-,M=I+1 IS J2 34 -'W4 IYE'S 1' NO I L J zse FTG. 6D Is NTHR-O? I NO YES T0 FIG.6G 6) T I. Q-ESTIMATED PROBABILITY. SEE REF.

READ-IN THRESHOLD PARAMETERS 2. CLAM- MEAN OF DIFFERENCE AT RECIS" TRATION.

3. NLEV-# OF STEPS IN THRESHOLD SEQUENCE. I 4. NMlN-1ST. POINT WHERE TEST TO BE PER- FORMED.

L 5. NMAX- POINT A'FTER WHICH THRESHOLD IS CONSTANT.

Jam. 7, 1975 D. 1. BARNEA ETAL 1930,00?

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 8 SUBROUTINE THGEN (N TE-HAVE IN RA E (GENERATES THRESHOLD DISCRETE VERSION SEQUENCE) OF THRESHOLD CURVES TABLE (I, J) /74 ND= (NMAX-NMINHNLEV QP= ALOGIO(Q) NO YEsl STOP FIG.6E

NMID= NMlD-NDZ SP= 1.0"S

NMID=NMID+ND IS NMID 50? NO YES[ 7 I Jan. 7, 1975 AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION D. I. BARNEA ETAL Original Filed June 16, 1972 l4 Sheets-Sheet 9 Fl G. 6F

R= IRI RP= 1.0 -R

RP* TABLE (IP,JP)

IS K2 YES NO I IS NMAX "ND2 50 NO YES L KP= K T(KP) 2.0 *T(KP1) -T(KP-2) r KP=KP+1 IS KP'Z NLEV YES NO I T(K)= m) *GLAM K= K+1 v IS K2 NLEV YES NO L..

WRITE OUT THRESHOLD s50.

Jan. 7, 1975 D. l. BARNEA ET AL T930,002

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 10 FIG.6G

SET ARRAY 38 IH(J) =0 J=1,1000

ILEV 0 NUMB =0 KMIN 10 40 IS=IS+1 JS=JS+1 I JS= 1 r y f IS NORMT=1 NO YES ILEV= NORMAL (IS, JS) IWLEV SUM ERRORS I B=S(KX+IS,KY+JS)- /48 THROUGH W(KX+1, KY+1)-ILEV 1 A=A+IB| 50 1 9 lSKzNMlN? YES NO |YEs L N0 Jan. 7, 1975 D. l. BARNEA ET AL AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 THRESHOLD SELECT VALUE 1 l4 Sheets-Sheet 1 1 FIG. 6H

YES

Jan. 7, 1975 BARNEA ET AL v T30,002

AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16, 1972 14 Sheets-Sheet 12 K= NMAX+1 KX =XN (K) KY YN (K) IS A TX YES NO IS K2 NLIST? YES NO IS K 1000 FIG.6I NO YES IH(K) IH(K) 1 IH(1000)= IH(1000)+1 IS NUMB 2 50 YES NO Jan. 7, 1975 D. BARNEA ETAL TQKWUZ AUTOMATIC PROCESS FAST DIGITAL IMAGE REGISTRATION Original Filed June 16 1972 14 Sheets-Sheet 14 ISIZSO'? ISIZSO? YES N0 NO YES I I 1 I= I 1 IS JS S5'W3 T'? YES N0 IS IS S4-W4 1 FIG. 6K

YES NO 64 WRITE OUT TABLE 66 WRITE OUT AV(I), X(I), Y(I),ITEST I) IS N2 NRUNS 1 YES NO STOP N: N +1 I TO FIG. 6A 3 

